Conventional wheelchairs have two large rear wheels rotatably mounted beneath a vertical side frame member and two caster wheels mounted to a rail or fork on the front of the wheelchair assembly. Conventional wheelchairs as presently manufactured cannot provide for a safe and “bump free” use by an occupant of the wheelchair to ascend or descend stairways. In order for a standard design wheelchair to be used in the transporting of an occupant up or down a stairway, the wheelchair must be tipped backward, with the occupant in it, by a handler or attendant of the wheelchair and then slowly lowered or raised, one step at a time on the stairway. Safe practice generally requires that a second attendant should grasp the front caster wheels or frame of the wheelchair and walk with the wheelchair as the occupant and wheelchair are raised or lowered on a stairway. Due to the size of the rear wheel, the wheelchair must be slowly lifted or lowered one stair at a time and in a manner that causes the occupant to be jolted or bumped as the wheels pass to the next step. This can, in extreme circumstances, lead to a total loss of control, resulting in a “free fall” situation for the occupant and/or the handler. In other circumstances, this can lead to anxiety and severe discomfort, particularly to older occupants of the wheelchair as well as individuals and persons suffering from injury or other trauma. And this can cause damage to the wheelchair as well. Further, using the wheelchair to ascend or descend a stairway is time consuming and places the occupant and handler at risk of injury due to the difficulty of a handler to control the wheelchair on the stairway, particularly on any stairway. Also, the handler must bend over the wheelchair at an uncomfortable angle when the wheelchair is tipped backwards on the stairwell. This leads to an uncomfortable experience for the handler, who must ensure that the wheelchair is lifted up and outward to clear a riser when ascending, as well as an increased risk to the safety of the wheelchair occupant and the handler.
Many wheelchair-bound persons, due to the difficulty of ascending or descending stairways and curbs, are prevented from gaining access to buildings and to the upper levels of multi-story buildings. Not only does this affect their mobility, but it also affects their ability to gain employment since many employers do not want to cope with a wheelchair-bound employee who cannot freely move from one floor to another in a place of employment. Also, hospitals, nursing homes and other multi-story patient care facilities must rely on elevators to move wheelchair-bound patients from one floor to another due to the difficulty of negotiating a stairway. Medical transport services that often transport sick, invalid, obese, or elderly patients have difficulty in transporting such patients in a wheelchair. Extreme difficulties have been encountered in the patients' homes where the wheelchair-bound person must be raised and lowered along a narrow stairwell. In many cases this prevents such a person from utilizing his or her whole house and forces him or her to live on only one floor of a multi-story dwelling.
Additionally, during a fire situation or other hazard when the elevators of most hospitals, nursing homes, and other multi-story buildings are shut down, residents are required to use stairways to exit the building. In so doing, particularly for wheelchair-bound invalids, there is a risk of injury, and great delay in removing them from the building in a safe and efficient manner. Such a delay also affects the ability of other building occupants to exit the building quickly and safely thereby increasing the risk of an overall panic where people are needlessly injured or killed. Current fire escape plans for many of these buildings involve placing a wheelchair-bound patient in a blanket and having four people, each carrying a corner of the blanket, remove the patient from the building. This method depends on the availability of four people strong enough to carry such a patient while ignoring the possible need for life sustaining equipment to be carried along with the patient. Therefore, the current state of emergency exit plans for most nursing homes and hospitals expose many of the wheelchair-bound and invalid patients to extreme danger in a fire situation.
Attempts have been made in the past to provide a means for ascending or descending stairs in a wheelchair in a manner that would not place the occupant at any risk of harm or jolt the occupant as the wheelchair is raised or lowered up the stairs. For example, some options include attaching a device to a standard wheelchair where: a) the device is permanently attached; b) the device is heavy and/or cumbersome to manufacture; and/or c) the device is expensive to own. Some other options provide for a special wheelchair equipped for ascending/descending stairs. Such wheelchairs are usually expensive to manufacture and conventional wheelchairs have to be replaced by such specialized wheelchairs to be able to take advantage of the stairway ascending/descending feature. Yet other options restrict the movement of the wheelchair both when the apparatus is in use and not in use. Frequently, all the above-indicated options require manual handling/control of the wheelchair by a handler to assist in moving the wheelchair up and/or down the stairs.
As is already evident, most conventional options for wheelchairs in assisting movement up or down a set of stairs have numerous disadvantages and problems. It would, therefore, be advantageous if an apparatus is developed, that while overcoming some, or all of the disadvantages and risks of the conventional options, also provides additional advantages. For example, instead of having the handler control the rate of ascent/descent, an apparatus that includes a motorized mechanism to move the wheelchair and occupant up and down the stairs would be beneficial. It would further be advantageous to provide a lightweight, easily-manufactured and affordable wheelchair apparatus capable of fitting to a wheelchair of a standard design for providing a safe and smooth means by which the wheelchair and occupant thereof can be raised or lowered on the stairway.
It would additionally be advantageous if an apparatus that is removably affixed to the wheelchair such that the apparatus can be removed from the wheelchair and conveniently stored if desired is developed. Such an apparatus would further provide an independent means of control not directly linked to the wheelchair handlebars for avoiding interference with the operation of the chair both when the apparatus is in use and not in use. Further, attaching such an apparatus to a wheelchair (or any other chair) would not interfere with the normal functioning of the wheelchair, allowing the wheelchair to function just as it would without the apparatus attached.